3 in 1 Design A MULTI-PURPOSE COROPLAST BOAT Ideal for all generations to enjoy. Weighs only 20 pounds! Drawn 06-20-2014 Ken Simpson Designs Rev. 09-25-2014 Print in Landscape Mode with ¼ inch borders. SPECIFICATIONS OAL = 7 feet (Power) OAL = 10 feet (Kayak) OAW = 30 inches OAH = 12 inches Weight = 20 pounds Capacity = 250 pounds max. (includes motor & battery) Speed = Approx. 4 MPH Build for less than $100 FEATURES Low Maintenance Design Fits in all Trucks & SUV's, and some larger Hatchback Cars. Can be built in about a week. Can easily be cartopped. Virtually unsinkable. Easy to repair. PARTS LIST 1 Sheet 4' x 8' x 4mm COROPLAST 1 sheet 4' x 8' x 1/4 Plywood 1 roll of Scotch Tough Tape 2 Tubes of 100% Silicone 32oz. Bottle of TB3 Glue 3-1 X 2 x 8' Lumber Various screws. Paint of choice. See end of plans for elongated versions. Power Boat on ramp, ready for first outing. This basic hull can be retrofitted with added modules to become a Kayak or Sailboat. Read plans thoroughly prior to starting construction. Page 1 of 29 This is an experimental design drawn up by an untrained amateur. The Designer accepts no liability for any loss, harm or damage sustained during construction or use. Builders may use these plans to construct a small quantity of boats for their own use only. Commercial manufacturers must ask the Designer for permission.
General Notes The idea for the came from the desire for a simple, lightweight, yet useful portable hull design.. It includes an ample beam, good freeboard, generous volume, seating for up to two, and safety buoyancy. It is reasonably sturdy, easy to build, very portable and can utilize a standard trolling motor. To have strength and yet be lightweight, the plans use some non-traditional methods of assembly, specifically the COROPLAST construction process developed and incorporated by the designer. Coroplast can be purchased at most local sign making companies, about $25 per sheet. This provides a durable, yet truly portable, finished boat, and the building process is easily mastered by the home handyman and amateur boat builder. As a result, only hand tools, a jig-saw, a hand drill, utility knife and a carpenters square, scissors, and tape measure are all that will be required throughout the assembly process. Be selective in your choice of materials. Use plywood that is preferably exterior rated. Marine Plywood is very expensive, so the use of ACX Grade is recommended, but be choosy. It is important to note, the final choice of materials is the decision of the builder. We have made specific recommendations, but if the builder has previous experience with different methods and materials, that is their choice, and we respect that decision. Certainly, minor changes in design are encouraged, to provide a 'custom' boat to satisfy a builders specific needs. We do not make changes to the drawings. This would be up to the individual builder, and their responsibility. Also, it is very important that none of the basic design parameters be drastically modified, as this may adversely affect overall boat safety or performance. Seating choice is also up to the builder. The folding plastic seat shown is $25 at Bass Pro sporting goods stores. I also have a folding plywood seat plan available for free download on the website, about $15 to build.. It should also be noted that the hull modules can be glued and screwed together, for those that do not have limitations of storage or transportation. Any questions or comments regarding the construction and/or design of this project will be responded to in a timely fashion. Thank you for your interest, and for purchasing these plans, and good luck with your project. And don t forget to visit www.portableboatplans.com for new designs and updates. Happy Boating! Ken Simpson, Designer Page 2
This is a Non-Fold-Up design. It should fit in all Trucks and SUV's, and some hatchbacks, like my PT Cruiser. 36 15 SPEC'S OAL = 84 OAW = 30 OAH = 12 Weight = 20 Cost = $100 2-1/2 Fold In Fold Out Fold In 4mm Coroplast Material 4' x 8' sheet, any color All lines are Creasing and Bending lines. 4 feet Skids 5 6 Silicone glue & screw transom to inside rear panel Fold In Trolling Motor or Paddle Powered Tape floorboard to side walls, and glue to base. Cut Out 6 1x4 Support Bar Fold In a ken simpson design Partial Creases 13 May 24-2014 Up to a 2 HP Motor. Fold In 1x2 Side Rails (outside) Tough Duct Tape All Edges & Seams In & Out BATT. Finished Hull Length = 7 feet 2x3 Motor Mount TRANSOM All Bends, No Cuts Tape Ends Closed Fold In FLOORBOARD 1/4 plywood floor & plywood transom, 1 x 2 lumber side rails Suggest rope steering for easier control Optional 28 Extension Module (see page 16) Finished Hull Weight = 20 pounds Alternate mechanical methods of joining the panels together can be utilized for greater security and reduced maintenance. A center bulkhead can also be used to enable a rope steering tiller and to provide additional structural rigidity. Assembly Steps: 1 - Mark, Crease & Fold as shown. 2 Clean all surfaces with denatured alcohol. 3 Silicone and Tape folds closed. 4 Tape all edges and seams. 5 Prepare side rails, floor board and transom. This includes cutting to size, and waterproofing. 6 Screw and glue in position all wood panels. Prepare skids, and glue and screw in place, from the inside. Page 3
The construction process of this boat will primarily be made of photos and text, briefly describing the different steps in assembly. The first step is to buy the 4 MM Coroplast 4' x 8' sheet material in the color of your choice. I like yellow or white. The material can be purchased at most Sign Companies, typically at $25 per sheet. I get mine at a franchised SIGNARAMA store. Because I do not have a truck or SUV, I have to fold the 4x8 sheet in half, to 4x4 size, to get it home in my PT Cruiser. This is done at the sign store parking lot, and does not affect the construction of the Coro Power Boat. MARKING The first thing is to clean the Coroplast surfaces with Denatured Alcohol, to remove any surface contaminates. MARKING Mark, per drawing on page 3, all bend lines, using a dark pencil, or Sharpie. Transom Area Bow Area CREASING CREASING Using a straightedge, and a dull pointed tool, crease the marked lines, as shown. I use a window screen assembly tool, but any non-sharp tool should work. Do not crease through the Coroplast. Transom Area Side Fold Page 4
FOLDED Bow Area Using a strong straightedge, like a 2x3 as shown, press firmly down on the bend line, and pull the Coropalst up slowly toward the straightedge. About half way up it will snap, and you can then bend the panel over. The photo at right is a good example of a corner bend line. FOLDED Transom Area Refer to Page 9 for crease & bend tools. Note the center bend, this is where I had to the bend the sheet in half to get it home. Bottom View The photo at right shows all the bends. Some have to be creased and bent from the opposite side of the sheet, such as the transom inside corner and the two side folds, and the center bow. Inside View NOTE: Some of these bends and folds are difficult to achieve, and require patience. An alternate method of assembly is to cut the corners away on the crease lines, which eliminates the folds. You can then butt the panels together, tape them on the outside, silicone the inside seam only, and then tape all the inside corners, using the Scotch Tough Duct Tape specified. Your choice. The downside is that this method can produce voids, and the possibility of allowing water to enter the hull. Folded corners prevent this from happening. Page 5
These 2 photos show the bow area bends. Note the 5 center cutout, the only one of the assembly. Note also the direction of the side bends. This provides better water flow of the hull. The photos below show what the finished bends look like at the various locations. Transom Corner Fold Side Fold Transom Outside View Side Fold Bow Bow Outside View Inside View Page 6
Bow Fold Deck and Inside View After all folds are made, and squeezed tight, it is now the time to add the 100% Silicone Adhesive. Lay down beads of adhesive, as shown below. Insure they are not too close to the edge, as it my squeeze out during assembly. Bring the panels together, and hold with small spring clamps. Or apply strips of Tough Tape to hold in place. 100% Silicone Adhesive, Clear Remember to be very cautious when applying the Silicone. If you get some on your hands, wash it off immediately. I suggest using DAWN soap, as it removes the adhesive well. TRANSOM Silicone Beads Allow the bonded panels to cure for at least eight hours (overnight). Patience is a virtue! TRANSOM Remember, wherever Silicone is present nothing else will stick. So use a reasonable amount, and do not get it on the outside surfaces. The primary purpose of using Silicone is to bond the panels together, for a better mechanical assembly. Because all seams are folded, no water will enter the hull. Page 7
Continue the bonding process as defined on the previous page. Scotch Tough Duct Tape Silicone Beads You may have to clamp the folds on the side panels, as shown at right. The hull also has 3 thicknesses of Coroplast here, and it is hard to get flat. Use strips of wood under the clamps so as not to indent the soft panels. Probably the most involved part of the assembly is the bow area. There are multiple bends and awkward shapes. Take your time. Align the top deck inside ends and bow point for proper fit. Use the Tough Tape to hold the bow tight together, and across the deck at both ends. Allow to cure overnight. Clamping Taped Seams Once all folds have been completed, it is time to apply Scotch Tough Tape to all the panel edges and seams. This seals the Coroplast edges, and prevents water from entering the individual corrugated cells. See photos on page 10. Page 8
These are the basic tools required to assemble the Coro Power Boat. The tape is very specific; It is Scotch brand Tough Duct Tape, No Residue. It has the best weatherability of any duct tape available. The other tools are generic, and the only requirement is that they be sharp and clean. Page 9
Applying the Scotch Duct Tape is easy. Unroll about a foot or two, and start at one end of a panel. Apply it so the edge of the panel is in the center of the tape. Tack it down each side of the panel at the same time. Press it firmly and smooth with your fingers. Unroll some more tape and repeat the process to the end of the panel, cut a with utility knife. Do the same for all edges, as shown below. If you make a mistake, you can pull the tape off and reposition it. But try to keep this to a minimum, as sometimes the tape will curl back onto itself, and that is difficult to undo. Bow Deck Although the tape is used for structural purposes, it also has to look good, so try to make the taped lines straight and even. Transom Corner In some cases you may want to apply more than one layer of tape, just to complete a corner, or for greater protection. The only inside seams that require taping are the 2 vertical side panel seams. Side Panel Note: Different colored tape can be applied elsewhere for decorative purposes. Bow Area Remember, it's the combination of mechanical fasteners (screws) and adhesive (tape & silicone) that makes the hull strong and waterproof. Page 10
Method of getting 2 floorboards and transoms out of one sheet of plywood. 28 4' x 8' Sheet of 1/4 plywood TRANSOM 6 1 FLOORBOARD 13 Floor Filler Approx. 42 FLOORBOARD 30 21 27 66 TRANSOM 14 Top View of Hull This double cut floorboard is only necessary if you are going to construct more than one hull. Otherwise, make the floorboard 6 feet long, to fill out the inside bottom of the hull. See photos on page 15. Storage Tape floorboard to side panels. KAYAK 250 pound capacity Bolted Together Storage Standard Coro Power Boat 2 Modules create a 10 foot long KAYAK Additional Aft Module See page 16 for detail. Page 11
At left is the completed Coroplast hull. As pictured with temporarily mounted side Rubrails. They will be the next step to cut, waterproof, and paint. These are made from 1 x 2 lumber, each about 52 long, with the outside edges rounded, for hand comfort. They will be held in place by #8 x 3/4 Phillips Head Truss Screws, from the inside. These are large head screws, and holes need to be pre-drilled, but the screws should not be overtightened, to protect the side panels from deforming too much. Waterproof the rubrails, per page 13, and paint with a good water resistant paint, oil based preferred. At the right is the inside floorboard, cut per the drawing on the previous page. The edges have been rounded smooth, and a coat of waterproofing has been brushed on both sides and edges, per the process on the following page. Next it will be painted a color to coordinate with the hull, probably blue. NOTE : If you do not need to make duplicate floorboards, as I did for building a second boat, you should extend the floorboard to a length of 6 feet, to completely fill out the inside floor. Page 12
. NOTE: Use this process for all wood panels and supports. Not for use on Coroplast. Page 13
The assembly photos are becoming less detailed, because you are becoming better at building the CPB. The following are photos of the Transom area and side Rubrail assembly. Note that the motor mount may be different than the drawing shows. Transom 2x3Trolling Motor Mount The left photo is the waterproofing of the Transom assembly. The 2x3 motor mount now extends to the outer edges of the transom panel. This provides greater support for the aft end of the hull. At right is a close-up of how the rubrail is screwed into the motor mount, for greater strength and rigidity. 2-1/2 Screw Note : The 2x3 motor mount is not necessary if you decide to build and use only the KAYAK version. At left is a photo of the #8 x 3/4 Truss Screws holding the 1x2 rubrail to the hull side panels. They are spaced about every 6. I did not silicone the rubrail to the side panels, but you could, for added strength #8 x 3/4 Phillips Head Truss Screws & security. At right is another view of the transom, siliconed to inside the rear hull panel, with an outer 1x2 support bar clamped to the hull rear panel until the silicone is cured. The next photos will concentrate on the forward support bar, and the 3 skids on the bottom of the hull, to complete the hull assembly. Page 14
The forward 27 long support bar is necessary for structural rigidity. I made mine from a 1 dowel, but a 1x2 would work fine. Fasten from the outside, through the rubrail, with a 21/2 long screw. Place as far forward on the rubrail as practical. Silicone in place. The forward support bar. 17 Flush The rear skids are about 4 feet long and 17 apart. The forward skid is about 32 long and on center. A second person is always a welcome helper! The skids are necessary to protect the bottom from damage. They are also made of 1x2 lumber, with the ends and edges rounded. Waterproof all over, and paint the sides and bottom, not the surface touching the Coroplast hull. First mark their location on the bottom. Next, drill 1/8 clearance holes 2 from the skid ends, and then about every 8 inches apart. Apply Silicone to skid. Hold in place, flush to transom end, and screw from inside, through the floor, with 1 long #6 wood screws. Hand tighten. Note: this detail has changed, see page 19 Closeup of support bar end. Completed Hull. Only a seat and paddles required. This completes the assembly, unless you want to build the hull extension, as defined next. Page 15
ELONGATED CORO BOAT 15 OPTIONAL Cut Out Completely fill the inside bottom with a 1/4 plywood floor. THIS IS AN EXTRA COST OPTION 90 deg. 28 sq. 6 Forward or Aft Module 6 Tape all hull seams and edges. Motor Extension Module Cut Cut Out Out Opt. Opt. 6 Transom The complete Hull Requires 2 sheets of 4mm Coroplast Center Module same but 4 feet long. Builders option. 15 Cut Out 48 This module is for the Elongated or Kayak hull assemblies. Cutouts necessary 2 Occupants in bulkheads for OAL = 10 feet 2nd occupant. Constructed similar to the Power Boat. 4 Cut Out Plywood Bulkheads used to reinforce bolt together assembly. Custom mount for larger motors. Plywood Transom FORWARD MODULE MOTOR MODULE CENTER MODULE 4' long NOT TO SCALE Glue floorboards to base panels. 1 x 2 rubrails on all modules Optional Double Ender Page 16
ELONGATED CORO BOAT OPTIONAL This is an additional tapered module, to be fastened to the hull transom, that converts the CPB into a KAYAK type hull. This Aft Module is constructed in much the same way as the hull, only shorter. Some of the bends are difficult, but the end result is worth it. At left are all the creases that need to be made. At right, all the bends have been formed. Creased & Bent Pre Assembly Cutouts The final shape is a triangle, and it fits the transom of the hull exactly. A plywood panel will be inserted and glued to the inside of the rear panel, similar to the transom. The photo at right shows the Aft Module mounted to the boat. It extends the water line another 3 feet, and provides excellent handling. Aft Module The aft module can be modified with a floorboard and skids. It is useful for gear storage, and the opening could be covered with a tarp. The following pages display photos of the finished boat, with some further detail, and in the water views. This was a great project! Page 17
ELONGATED CORO BOAT OPTIONAL 4 Aft Module Top 1x2 Inside Support Inside Panel Cut ends 45 degrees Tape after Silicone is cured. Silicone all around panel The inside Panel is about 27 long and high, but should be cut to fit. Note the 1x2 support, which will be used to support the Aft Module to the Hull. Waterproof the assembly before painting. Apply Silicone to all inside folds of the Coroplast bends, and the outside that will be in contact with the Panel. Install the same way you did for the Transom. As with the hull design in general, changes can be made to accommodate any ideas you may have for the boat. Mounting of the two modules is easy, and requires only two 5/16 x 3-1/2 long bolts. See next page for more detail. Remember to apply silicone in the 3 corners of the rear panel to hull insides. 1x2 Support Panel Installed 4 4 #8 x 3/4 Truss Screws All wood panels and attachments must be waterproofed prior to painting. The Coroplast panels require no preservation treatment. Page 18
Steering Pulley 6 Steering rope Module assembly bolts Some detail photos of the finished hull modules. The boat has been set up for rope steering while under trolling motor power. Also, a canopy top has been fitted, and the hold down bungees are attached. Also please note the change to the forward support bar. The straight one has been replaced with an arched one for better leg room. It was cut from a scrap 1 x 4 x 27 long. And, the 2 hull module assembly bolts (5/16 x 3-1/2 long) have been installed, 6 up from the bottom and 16 apart, held firm by large washers and wingnuts. View from aft module More legroom Steering Rope 16 Assembly Bolts Folding plastic seat NEW arched forward support bar Page 19
COROPLAST HULLS Can be made larger or longer, depending on your needs. Keep the material selection simple and lightweight. OPTIONAL CANOPY See photos THIS IS AN EXTRA COST OPTION Top made of lightweight tarp material. Canopy Bow Supports (2) 1/2 Plywood About 9 x 6 size 1/4 Bolt Holes 45 33 34 5/16 Bolt Hole Supports are 1 thin wall PVC pipe. Bungee 1/4 Dowel Easily removable with the use of Bolt Knobs and T-Nuts on the 1x2 side supports. Nylon Cord The dowel prevents the support from rotating. 22 Extension 80 WLL 5/16 Bolt 1/4 Dowel Page 20
Optional Canopy Top IN THE SHOP The optional canopy top is necessary in sunny climates, and works best in the power boat mode. The vertical supports do hinder paddling. The cost of the canopy assembly is less than $20, so it is a worthwhile option. Changes to the size and setup should be made to satisfy your particular needs. Construction details are not necessary, due to the simplicity of the design. Notice the new red tape stripes! ON THE WATER The made its maiden voyage on 8-26-2014. I first tested it in the KAYAK mode (as shown at left) for stability, ease of paddling and directional control. I weigh 160, and it only settled 2 inches into the water, providing easy handling. It paddled effortlessly, and wandered very little, due to the nice long waterline. I then switched over to the Trolling Motor version, which takes only a few minutes. In this mode, the boat draws about 3 inches of water, due primarily to the 48 pound 80 AH deep cycle battery that I use. Still plenty of freeboard though. However, I am going to buy a 35 AH battery, to reduce the weight I have to carry by 20 pounds. The boat performs well under power, about 4 MPH with a 2 blade prop, and is comfortable and stable. No leaks were observed! Page 21
Trolling Motor Power Boat Paddle Power Kayak Forward Battery Location Observed Waterline Trolling Motor Setup Stored in PT Cruiser for the trip home. Although I enjoy not paddling (motor power), I think most people will choose the KAYAK version for its ease of use, and low entry cost. Happy boating! Page 22
ELONGATED CORO BOAT OPTIONAL These are assembly photos of the 28 inch Motor Extension Module (see page 16). This will have a plywood floor and a plywood bulkhead and transom. The transom will have the 2x3 Motor Mount option. The purpose of the module is to increase boat load capacity by 75 pounds, and hull speed by about 1 mph. Total hull capacity will now be 325 pounds, with a hull speed of 5 mph. Note the 45 degree corner fold, which will be at the bulkhead and transom ends. All panels creased and folded. This is the same method as used for the main hull. Hulls assembled, motor and battery installed, and the seat repositioned. There is now a lot of legroom. Bulkhead and Transom installed, and Floor is weighted down while being Silicone bonded to the hull panels. The finished module ready for assembly to the main hull. The same 2 bolt method of securing them together as the Kayak module, page 19. Page 23
ELONGATED CORO BOAT OPTIONAL Water Line Actual speed on water of 4.1 mph Aft view, showing the rope steering. Optional Sun Canopy Top Plenty of legroom in the extended version. Top support assembly detail. Draft, fully loaded, is only 2 inches. Canopy top folded forward, for entry & exit. These photos depict the third configuration of the Coro Power Boat. There is the basic hull, which can be rowed, paddled or motorized. Then there is the Kayak version, strictly for effortless paddling. And finally, this Extended version, primarily for greater load capacity. Each has its own attributes, but combined, they provide a craft that is multi-capable. There is even a longer extended version which can be modified to accept two occupants, by lowering the center of the bulkheads, as shown on page 16. In testing, I found the hull to be very stable, as long as the seat is kept low to the floor, as shown. Hull speed is achieved quickly and smoothly, with little hull wake. But the primary feature of this design is the low hull weight, 20 pounds. Easy to lift into and out of your vehicle. And, because all modules utilize folded corners and seams, there is no chance of water entering the hull. The skids provide hull bottom protection, and also help the hull from drifting while paddling. Overall, I am very pleased with this third generation Coroplast hull design. Thanks for your interest. Ken Page 24
Small pulleys would reduce rope friction, for smoother steering.
POTENTIAL SAILBOAT COROPLAST HULLS CONCEPT ONLY With proper structural supports, the mast, leeboards and rudder can all be added to produce a simple, yet exciting, sailing version of the Coro Power Boat. 11' Mast Sail area = 35 sq.ft. 3 Stays No Boom Halyard Sheet Vang 15 Seating type is optional. Can be a removable bench seat the width of the hull. Rudder & Tiller Assembly mounts to back of Transom. Rope Steering Flotation Noodles Buoyancy Ball Mast Step Standard Coro Power Boat 42 Motor Module Kick-up Rudder Twin Retractable Leeboards Page 28
COROPLAST HULLS CONCEPT ONLY 3 Module 10' Canoe (nesting type for transport) Side Motor Mount 26 Capacity = 250 pounds max. The CANOE option is but another variation of the Coro Boat theme. It will fit in most cars for transport, and provides very good balance and handling for one, when in the water. 30 All new slanted side Coro Hull. Similar in construction to the CPB, but sides slanted 2 per side.. Front View Optional side mounted trolling motor Plywood Bulkheads 9 2-1/2' 4' 3-1/2' Page 29